The present invention relates to a level indicating device and specifically to a level which emits an audio signal and a visual signal when the desired level condition is attained by the device.
There are many instances where a solitary workman needs to adjust a workpiece to a level condition from a site remote from the place where the level condition is desired. In other instances, the level must be placed at a site that is not accessible to a person, and thus the observer of the level must remain at a location remote from the level's location. Moreover, the lighting conditions at the workplace are not always ideal for reading a conventional gas bubble type level. In such circumstances, a level indicating device which emits an audible signal or a visual signal upon attaining a level condition enables the workman to make the adjustment without requiring the presence of a second workman at the site where the level indicating device is placed to read when the level condition has been attained.
In U.S. Pat. No. 723,526 to Hein, a leveling staff has a pendulum which forms a complete electric circuit with an incandescent lamp and an electric bell when the pendulum is parallel to the longitudinal axis of the staff. U.S. Pat. No. 3,233,235 to Wright discloses a signaling level having a pendulum which magnetically activates a switch that closes a circuit and lights a light or sounds a buzzer when the level rests in an horizontal position. The pendulum is mounted on a rotatable, angularly adjustable dial which must be rotated depending upon whether the level is required to sense a vertical or an horizontal condition.
In some applications, it is desirable to have a level sensing device which is capable of sensing both an horizontal and a vertical condition either simultaneously or consecutively without any intervening adjustment of the device between sensing the vertical condition and sensing the horizontal condition.